1. Field of the Invention
The present invention relates to an ultrasonic generator which is necessary for an ultrasonic sterilizer development task, and its manufacturing method. More particularly, it relates to an ultrasonic generator and its manufacturing method which can minimize the heat input of a magnetostrictive element, instead of a furnace heating method under existing pressure conditions, in order to join the magnetostrictive element with a wave guide.
2. Discussion of Related Art
A sterilization treatment is a result of constant devotion to the human health in modern civilized living.
Therefore, there is a necessity for the sterilization in medical care, chemistry, food, electronics, and everyday life.
A conventional chemical sterilization treatment is gradually converted into electronic one due to toxicity of chemical agents itself and poison of residual materials.
In this regard, an ultrasonic sterilizer has been developed.
As shown in FIG. 1, an ultrasonic generator for ultrasonic sterilizer includes a layered magnetostrictive element one, and a wave guide 2 connected to a join surface 3 formed at the front of the magnetostrictive element.
It is necessary that the magnetostrictive element and the wave guide are uniformly and firmly joined to each other with a relatively broad join area over approximately 750 800 mm.sup.2.
Considering the magnetic characteristics variation factor of the magnetostrictive element in response to the heat-affection, a joining method for applying less heat input to a joining portion, and the joining materials with proper intensity of joining should be selected.
In a conventional high-temperature furnace heating method, a base metal and the joining materials melt to be welded under pressure conditions, causing the magnetostrictive element to be deteriorated in its ultrasonic sound pressure and durability.